DB2 for LUW has supported automatic statistics collection since V8.2. But even automatic statistics collection may notcollect statistics soon enough for certain workloads. DB2 9.5 adds the capability to collect statistics when the query optimizerneeds them - at statement compilation time. DB2 for LUW supports a number of low overhead methods to fabricate or collectstatistics while a statement is being compiled. Statistics are immediately made available to other queries through anew statistics cache. Background statistics collection is improved so that it occurs sooner than before, to ensure your tablesalways have the most current statistics. A number of new monitoring, logging and Explain features have been added to helpyou understand all forms of DB2 statistics collection, whether it is done manually by you with the RUNSTATS command orautomatically by DB2.

EXP. LEVEL: Intermediate

OBJECTIVES:

Understand the various ways DB2 for LUW can collect statistics

Understand how synchronous statistics collection and fabrication work

Understand how and when asynchronous statistics collection occurs

Learn how the statistics cache works

Learn what monitoring and logging features are available understand statistics activities

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